Process for making solvents for acetyl-cellulose plastics.



WILLIAM G. LINDSAY, or CALDWELL. new JERsRY, AssIenoR TO THE CELLULOID COMP-ANY, or NEW YoRK, N. 55., A CORPORATION or new JERSEY.

PROCESS FOR MAKING SOLVENTQTOR ACETYL-CELLULOSE PLASTICS.

Specification of Letters Patent.

Patented 0a. 2a, 1917.

No Drawing. Application filed November 6, 1911, Serial No. $8,786. Renewed March 20, 1917. Serial To all whom it may concern:

Be it known that I, WILLIAM G. LINDSAY, a citizen of the United States, residing in Caldwell, county of Essex, State of New J ersey, have invented a certain new and useful Process for Making Solvents for Acetyl- Cellulose Plastics, of' which the following is a specification.

The various compositions to which the present invention relates are employed in the arts, generally as imitations of natural substances, sometimes in their original finished form with or without incorporated colors, and sometimes as films which are used for photographic and other purposes.

Although the final or useful form of the different compounds of acetyl cellulose is that of a solid or dried material, the difierent processes of conversion into this final solid form involve, as is well understood, the employment of solutions or mixtures of varying consistency asto plasticity, stiffness or fluidity, depending generally upon the proportion and kind of solvent usedto the amount of the original baseacetyl cellulose.

It has long beenv known that camphor mixed with nitro cellulose upon the addition of ethyl alcohol to the mixture becomes a solvent of the nitro cellulose. I have found, however, that when that process is applied to acetyl cellulose no solvent action takes place in the cold, and the ob]ect of my invention was to find substances which, when added to the acetyl cellulose would, upon the subsequent addition ofethylalcohol, exert a solvent action upon the cellulose and produce a plastic mass which could be worked in a manner analogous to nitro cellulose-camphor compounds.

I have discovered that not all of the socalled camphor substitutes possess this property when used with acetyl cellulose, and in the course of my experiments I have found that camphor substitutes may be grouped into three classes with respect to their ,solvent action on acetyl cellulose, namely Class A: Those substances which are non solvents when melted, or when dissolved in either ethyl or methyl alcohol in the cold, or room temperature; such as triphenylphosphate, tricresylphosphate, and naphthalene.

Class 13: Those substances which become solvents when melted, but are non-solvents when dissolved in ethyl alcohol at room temperature; such as camphor, tetrachlorethyl acentanilid, and trichlormethyl acetanilid. Class C: Such substances as become solvents when melted and also become solvents when dissolved in methyl or ethyl alcohol in equal parts by weight at room temperature;

. such as toluol-sulfonamid, ethyl para toluolsulfonamid, benzene-sulfonamid, ethyl ace-.

tanilid, and methyl acetanilid.

I have also discovered that in making fiowable solutions from my new compounds, I can employ substances other than those mentioned, and Ihave accordingly divided this application into four divisions, each forming the sub-jectof a separate application and designated by the letters A, B, C, and D, respectively.

a In order to carry out the new process which forms the subject matter of this application (Division D), as one example, I incorporate 100 parts of an acetyl cellulose which is soluble in acetone with 20 to 50 parts of ethyl para toluol-sulfonamid by suitable grinding and mixing, as is the practice in the nitro cellulose art. To such mixture I add from 40 to 100 parts of ethyl or of methyl alcohol, or a mixture of the two, and after thorough incorporation by stirring, the mixture is allowed toremain at room temperature in a closed vessel for from 5 to 24 hours, or longer, the length of time depending upon the physical form of the acetyl cellu ose used; that is, whether it is finely or coarsely ground. In the course of time the mixture will have become converted into a more or less stiff gelatinated mass. It can then be Worked up on rolls or a kneading machine, according to the practice which is common in the nitro cellulosecamphor plastic art, and the resulting product may then be molded or passed through the stuffing machine as in the case of nitro cellulosecamphor compounds.

I have found that a mixture composed of 1 part by weight each of ethyl alcohol and ethyl para toluol-sulfonamid is a more powerful solvent that a mixture of 2 parts by weight of ethyl alcohol and 1 part by weight of ethyl para toluol-sulfonamid. If the alcohol is increased beyond this proportion the solvent power rapidly decreases; hence it is desirable to use as small a proportion of alcohol as possible in converting the acetyl cellulose into a gelatinous mass, but the application of heat will restore to a certain extent the solvent action of a solvent mixture which is otherwise too weak. A proportion of'1.5 parts of ethyl or methyl alcohol to 1 part of ethyl para toluol-sulfonamid also produces very satisfactory results as agelatinating agent for acetyl cellulose.

Instead of the ethyl para toluol-sulfonamid I can use benzene-sulfonamid, and also ethyl acetanilid and related derivatives.

In order'to produce fiowable solutions in the cold from the gelatinous mass made according to the process above described and solutions which are suitable for filtering, etc.,

v I have found that suitable solvents or diluents for such purposes are produced by incorporating with the mass, mixtures of either ethyl or methyl alcohol with the following liquids in the proportions hereinafter described. These liquids are chloro: form, epichlorhydrin, aceto-dichlorhydrin,

v dichlor-ethylene, ethylene-chlorid, tri-chlor- .a solvent mixture, the addition of a camphor substitute of Class reestablishes the solvent action.

In' order to convert the gelatinous mass produced according to the process above described into. a more fluid mixture which can be filtered, etc., I use a mixture of methyl or ethyl alcohol containing from 20% to 40% by volume of any of the above liquid substances. To 1 part of the gelatinous mass I add from 1 to 4 parts of this compound solvent, or sufficient to produce a product of the desired fluidity, and incorporate it by mixing, kneading, stirring or malaxating. After filtration or other treatment, the solution of acetyl cellulose thus pro duced is worked up in the usual manner by evaporating the excess of solvent and further kneading, pressing, etc., the resultant mass. Here, again, I have found that if the solvent is too weak, theapplication of heat will restore the solvent action.

If it is desired to produce anon-inflamma- A above set forth astriphenylphosphate I dichlorhydrin,

naaasae which eiiect non-i'nfiammability in the resultant mass. That is, the inflammability of the plastic masses made by the use of camphor substitutes .of Class C can be reduced and overcome by incorporating such camphor substitutes as triphenylphosphate which belong to Class A. I have found that this can be accomplished by proceeding as follows I incorporate with 100 parts of acetyl cellulose, 20 parts of ethyl para toluol-sulfonamid and 20 parts of triphenylphosphate, and after thorough grinding, mix1ng,'

etc., I add $0 #5060 parts of methyl or ethyl alcohol, but I prefer methyl alcohol. The gelatinous mass produced by allowing this mixture to stand at room temperature in an air tight receptacle is further worked up by kneading, etc., according to practices well known to the nitro cellulose art. If it is desired to produce a more fluid solution, the

alent substances for the purposes of this vention as toluol-sulfonamid ethyl para toluol-sulfonamid, and benzene-sulfonamid. Similarly, equivalents for chloroform for producing a flowable solution in the cold as aforesaid comprise epichlorhydrin, acetodichlorethylene, ethylenechlorid, trichlorhydrin, pentachlorethane, acetochlorhydrin, acetylene tetrachlorid, chloracetate of ethyl, acetone, ethyl acetate and di-acetochlorhydrin.

By ethylparatoluolsulfonamid, I mean the compound having the following structural formula the same being an alkylated aromatic sulbranches of the invention or inventions described in this specification, I have, as

'stated, divided'the subject matter into four separate applications with claims corresponding accordingly and in this application (Division D).

I claim as follows: 7

1. The new compound solvents for an acetyl cellulose whichi's soluble in acetone consisting in a mixture of a monohydric alcohol havinig not more than two carbon atoms and an aryl-sul'fonainid, the proportion being about 40 to 100 parts by weight of the ing about 40 to 100 parts by weight of the former to about to 50 parts of the latter.

2. The new compound solvents for an acetyl cellulose which is soluble in acetone consisting in a-mixture of a monohydric alcohol having not more than two carbon atoms and from 10 to 40% of a liquid adapted to produce a fiowable solution in the cold and an aryl-sulfonamid.

3. The new compound solvents for an acetyl cellulose which is soluble in acetone consisting in a mixture of a monohydric alcohol having not more than two carbon atoms and a toluol-sulfonamid, theproportion beformer to about 20 to parts of the latter.

4. The new compound solvents for an acetyl cellulose which is soluble in acetone consisting in a mixture of a monohydric alcohol having not more than two carbon atoms, said mixture'further comprising from 10 to 40 per cent. of chloroform, and an aryl sulfonamid.

IRVING M. WEIss, H. HINDON HYDE. 

